The invention relates to the field of optical measurements and connections and relates more particularly to a compact optical coupling device providing a rigid mechanical connection between a radiation separating element and ends of optical fibers.
When an optical device formed by discrete elements receives the radiation from a laser source and must transmit it, after separation, to optical fibers, monomode for example, it is absolutely necessary to carry out very accurate adjustments, so that the coupling losses are as small as possible during coupling of the radiation into the fiber or fibers where it is to be transmitted. In particular, the radiation from the source must be focused, and the ends of the fibers must be very accurately positioned so that the plane of the end passes through the focusing point. Thus, the coupling losses are minimized.
This is in particular the case for an optical-fiber gyrometer in which the radiation from the laser source is transmitted after separation into two equal parts to the two ends of the same coiled-up optical fiber. For the coupling losses to be minimum, the separating element and the ends of the fiber must be very accurately located in relation to each other. Moreover, the positioning must be fixed so that the signal received after recombination of the waves emerging from the fiber after having traveled in opposite directions is stable in time when the rotational speed of the gyrometer is constant.
The invention proposes a compact optical coupling device which avoids the drawbacks of the coupling devices formed from separate elements and which requires then no adjustment. Such a device has the advantage of stability, the positioning of its components in relation to each other being permanently provided and incapable of being modified.